consulate in benghazi, libya. the president condemned the video, but he insisted there is no justification for mindless violence. >> given the power of faith in our lives and the passion that religious differences can inflame, the strongest weapon against hateful speech is not repression. it is more speech. the voices of tolerance that rally against bigotry and blasphemy and lift up the values of understanding and mutual respect. >> woodruff: mr. obama also had a new warning on iran's nuclear program. yesterday iranian leader ahmadinejad repeated his claim that the program is only for peaceful purposes, an explanation the u.s. and other countries dismiss. today the president said again iran cannot be allowed to build nuclear weapons. >> let me be clear. america wants to resolve this issue through diplomacy. we believe that there is still time and space to do so. but that time is not unlimited. make no mistake, a nuclear-armed iran is not a challenge that can be contained. it would threaten the elimination of israe